Number of directed, diagonally convex polyominoes with n cells.

Terms

a(0) =1a(1) =0a(2) =3a(3) =10a(4) =33a(5) =106a(6) =331a(7) =1009a(8) =3017a(9) =8884a(10) =25841a(11) =74416a(12) =212533a(13) =602785a(14) =1699503a(15) =4767166a(16) =13312641a(17) =37031254a(18) =102651967a(19) =283676689a(20) =781763381a(21) =2149017256a(22) =5894114513a(23) =16132400860a(24) =44071485673a(25) =120188174401a(26) =327242994651